Vaccine Trial Results Prove Confusing

AIDSVAX, an experimental vaccine developed by VaxGen, does not provide significant protection against HIV infection, reducing overall infection rates among clinical trial participants by just 3.8%, company officials announced on February 24. AIDSVAX is the first HIV vaccine to make it to Phase III clinical trials, and more than 5,000 participants, including women perceived to be at high risk for infection and sexually active gay and bisexual men, took the vaccine in the three-year study. But while the overall trial results were discouraging, VaxGen officials did report that the vaccine may be useful for African-Americans and Asians, who as study subgroups fared better. Based on these findings, VaxGen officials say they planned to continue developing AIDSVAX for possible use in these communities. 'This is the first time we have specific numbers to suggest that a vaccine has prevented HIV infection in humans,' VaxGen vice president Phillip Berman says. 'We're not sure yet why certain groups have a better immune response.' The company is expected to announce the results of another Phase III clinical trial in the fall that includes 2,400 injection-drug users.